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765b7590c9
r8152 conflicts are the NAPI fixes in 'net' overlapping with some tasklet stuff in net-next Signed-off-by: David S. Miller <davem@davemloft.net>
354 lines
13 KiB
C
354 lines
13 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/* Copyright (c) 2019, Vladimir Oltean <olteanv@gmail.com>
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*
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* This module is not a complete tagger implementation. It only provides
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* primitives for taggers that rely on 802.1Q VLAN tags to use. The
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* dsa_8021q_netdev_ops is registered for API compliance and not used
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* directly by callers.
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*/
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#include <linux/if_bridge.h>
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#include <linux/if_vlan.h>
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#include "dsa_priv.h"
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/* Binary structure of the fake 12-bit VID field (when the TPID is
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* ETH_P_DSA_8021Q):
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*
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* | 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
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* +-----------+-----+-----------------+-----------+-----------------------+
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* | DIR | RSV | SWITCH_ID | RSV | PORT |
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* +-----------+-----+-----------------+-----------+-----------------------+
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*
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* DIR - VID[11:10]:
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* Direction flags.
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* * 1 (0b01) for RX VLAN,
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* * 2 (0b10) for TX VLAN.
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* These values make the special VIDs of 0, 1 and 4095 to be left
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* unused by this coding scheme.
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*
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* RSV - VID[9]:
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* To be used for further expansion of SWITCH_ID or for other purposes.
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* Must be transmitted as zero and ignored on receive.
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*
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* SWITCH_ID - VID[8:6]:
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* Index of switch within DSA tree. Must be between 0 and
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* DSA_MAX_SWITCHES - 1.
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*
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* RSV - VID[5:4]:
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* To be used for further expansion of PORT or for other purposes.
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* Must be transmitted as zero and ignored on receive.
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*
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* PORT - VID[3:0]:
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* Index of switch port. Must be between 0 and DSA_MAX_PORTS - 1.
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*/
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#define DSA_8021Q_DIR_SHIFT 10
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#define DSA_8021Q_DIR_MASK GENMASK(11, 10)
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#define DSA_8021Q_DIR(x) (((x) << DSA_8021Q_DIR_SHIFT) & \
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DSA_8021Q_DIR_MASK)
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#define DSA_8021Q_DIR_RX DSA_8021Q_DIR(1)
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#define DSA_8021Q_DIR_TX DSA_8021Q_DIR(2)
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#define DSA_8021Q_SWITCH_ID_SHIFT 6
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#define DSA_8021Q_SWITCH_ID_MASK GENMASK(8, 6)
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#define DSA_8021Q_SWITCH_ID(x) (((x) << DSA_8021Q_SWITCH_ID_SHIFT) & \
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DSA_8021Q_SWITCH_ID_MASK)
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#define DSA_8021Q_PORT_SHIFT 0
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#define DSA_8021Q_PORT_MASK GENMASK(3, 0)
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#define DSA_8021Q_PORT(x) (((x) << DSA_8021Q_PORT_SHIFT) & \
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DSA_8021Q_PORT_MASK)
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/* Returns the VID to be inserted into the frame from xmit for switch steering
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* instructions on egress. Encodes switch ID and port ID.
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*/
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u16 dsa_8021q_tx_vid(struct dsa_switch *ds, int port)
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{
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return DSA_8021Q_DIR_TX | DSA_8021Q_SWITCH_ID(ds->index) |
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DSA_8021Q_PORT(port);
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}
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EXPORT_SYMBOL_GPL(dsa_8021q_tx_vid);
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/* Returns the VID that will be installed as pvid for this switch port, sent as
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* tagged egress towards the CPU port and decoded by the rcv function.
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*/
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u16 dsa_8021q_rx_vid(struct dsa_switch *ds, int port)
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{
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return DSA_8021Q_DIR_RX | DSA_8021Q_SWITCH_ID(ds->index) |
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DSA_8021Q_PORT(port);
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}
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EXPORT_SYMBOL_GPL(dsa_8021q_rx_vid);
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/* Returns the decoded switch ID from the RX VID. */
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int dsa_8021q_rx_switch_id(u16 vid)
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{
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return (vid & DSA_8021Q_SWITCH_ID_MASK) >> DSA_8021Q_SWITCH_ID_SHIFT;
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}
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EXPORT_SYMBOL_GPL(dsa_8021q_rx_switch_id);
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/* Returns the decoded port ID from the RX VID. */
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int dsa_8021q_rx_source_port(u16 vid)
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{
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return (vid & DSA_8021Q_PORT_MASK) >> DSA_8021Q_PORT_SHIFT;
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}
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EXPORT_SYMBOL_GPL(dsa_8021q_rx_source_port);
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static int dsa_8021q_restore_pvid(struct dsa_switch *ds, int port)
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{
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struct bridge_vlan_info vinfo;
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struct net_device *slave;
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u16 pvid;
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int err;
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if (!dsa_is_user_port(ds, port))
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return 0;
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slave = ds->ports[port].slave;
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err = br_vlan_get_pvid(slave, &pvid);
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if (err < 0)
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/* There is no pvid on the bridge for this port, which is
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* perfectly valid. Nothing to restore, bye-bye!
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*/
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return 0;
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err = br_vlan_get_info(slave, pvid, &vinfo);
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if (err < 0) {
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dev_err(ds->dev, "Couldn't determine PVID attributes\n");
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return err;
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}
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return dsa_port_vid_add(&ds->ports[port], pvid, vinfo.flags);
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}
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/* If @enabled is true, installs @vid with @flags into the switch port's HW
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* filter.
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* If @enabled is false, deletes @vid (ignores @flags) from the port. Had the
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* user explicitly configured this @vid through the bridge core, then the @vid
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* is installed again, but this time with the flags from the bridge layer.
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*/
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static int dsa_8021q_vid_apply(struct dsa_switch *ds, int port, u16 vid,
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u16 flags, bool enabled)
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{
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struct dsa_port *dp = &ds->ports[port];
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struct bridge_vlan_info vinfo;
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int err;
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if (enabled)
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return dsa_port_vid_add(dp, vid, flags);
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err = dsa_port_vid_del(dp, vid);
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if (err < 0)
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return err;
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/* Nothing to restore from the bridge for a non-user port.
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* The CPU port VLANs are restored implicitly with the user ports,
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* similar to how the bridge does in dsa_slave_vlan_add and
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* dsa_slave_vlan_del.
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*/
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if (!dsa_is_user_port(ds, port))
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return 0;
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err = br_vlan_get_info(dp->slave, vid, &vinfo);
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/* Couldn't determine bridge attributes for this vid,
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* it means the bridge had not configured it.
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*/
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if (err < 0)
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return 0;
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/* Restore the VID from the bridge */
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err = dsa_port_vid_add(dp, vid, vinfo.flags);
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if (err < 0)
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return err;
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vinfo.flags &= ~BRIDGE_VLAN_INFO_PVID;
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return dsa_port_vid_add(dp->cpu_dp, vid, vinfo.flags);
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}
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/* RX VLAN tagging (left) and TX VLAN tagging (right) setup shown for a single
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* front-panel switch port (here swp0).
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*
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* Port identification through VLAN (802.1Q) tags has different requirements
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* for it to work effectively:
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* - On RX (ingress from network): each front-panel port must have a pvid
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* that uniquely identifies it, and the egress of this pvid must be tagged
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* towards the CPU port, so that software can recover the source port based
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* on the VID in the frame. But this would only work for standalone ports;
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* if bridged, this VLAN setup would break autonomous forwarding and would
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* force all switched traffic to pass through the CPU. So we must also make
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* the other front-panel ports members of this VID we're adding, albeit
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* we're not making it their PVID (they'll still have their own).
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* By the way - just because we're installing the same VID in multiple
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* switch ports doesn't mean that they'll start to talk to one another, even
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* while not bridged: the final forwarding decision is still an AND between
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* the L2 forwarding information (which is limiting forwarding in this case)
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* and the VLAN-based restrictions (of which there are none in this case,
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* since all ports are members).
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* - On TX (ingress from CPU and towards network) we are faced with a problem.
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* If we were to tag traffic (from within DSA) with the port's pvid, all
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* would be well, assuming the switch ports were standalone. Frames would
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* have no choice but to be directed towards the correct front-panel port.
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* But because we also want the RX VLAN to not break bridging, then
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* inevitably that means that we have to give them a choice (of what
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* front-panel port to go out on), and therefore we cannot steer traffic
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* based on the RX VID. So what we do is simply install one more VID on the
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* front-panel and CPU ports, and profit off of the fact that steering will
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* work just by virtue of the fact that there is only one other port that's
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* a member of the VID we're tagging the traffic with - the desired one.
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*
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* So at the end, each front-panel port will have one RX VID (also the PVID),
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* the RX VID of all other front-panel ports, and one TX VID. Whereas the CPU
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* port will have the RX and TX VIDs of all front-panel ports, and on top of
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* that, is also tagged-input and tagged-output (VLAN trunk).
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*
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* CPU port CPU port
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* +-------------+-----+-------------+ +-------------+-----+-------------+
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* | RX VID | | | | TX VID | | |
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* | of swp0 | | | | of swp0 | | |
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* | +-----+ | | +-----+ |
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* | ^ T | | | Tagged |
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* | | | | | ingress |
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* | +-------+---+---+-------+ | | +-----------+ |
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* | | | | | | | | Untagged |
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* | | U v U v U v | | v egress |
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* | +-----+ +-----+ +-----+ +-----+ | | +-----+ +-----+ +-----+ +-----+ |
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* | | | | | | | | | | | | | | | | | | | |
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* | |PVID | | | | | | | | | | | | | | | | | |
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* +-+-----+-+-----+-+-----+-+-----+-+ +-+-----+-+-----+-+-----+-+-----+-+
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* swp0 swp1 swp2 swp3 swp0 swp1 swp2 swp3
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*/
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int dsa_port_setup_8021q_tagging(struct dsa_switch *ds, int port, bool enabled)
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{
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int upstream = dsa_upstream_port(ds, port);
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u16 rx_vid = dsa_8021q_rx_vid(ds, port);
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u16 tx_vid = dsa_8021q_tx_vid(ds, port);
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int i, err;
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/* The CPU port is implicitly configured by
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* configuring the front-panel ports
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*/
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if (!dsa_is_user_port(ds, port))
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return 0;
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/* Add this user port's RX VID to the membership list of all others
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* (including itself). This is so that bridging will not be hindered.
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* L2 forwarding rules still take precedence when there are no VLAN
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* restrictions, so there are no concerns about leaking traffic.
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*/
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for (i = 0; i < ds->num_ports; i++) {
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u16 flags;
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if (i == upstream)
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continue;
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else if (i == port)
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/* The RX VID is pvid on this port */
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flags = BRIDGE_VLAN_INFO_UNTAGGED |
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BRIDGE_VLAN_INFO_PVID;
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else
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/* The RX VID is a regular VLAN on all others */
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flags = BRIDGE_VLAN_INFO_UNTAGGED;
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err = dsa_8021q_vid_apply(ds, i, rx_vid, flags, enabled);
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if (err) {
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dev_err(ds->dev, "Failed to apply RX VID %d to port %d: %d\n",
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rx_vid, port, err);
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return err;
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}
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}
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/* CPU port needs to see this port's RX VID
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* as tagged egress.
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*/
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err = dsa_8021q_vid_apply(ds, upstream, rx_vid, 0, enabled);
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if (err) {
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dev_err(ds->dev, "Failed to apply RX VID %d to port %d: %d\n",
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rx_vid, port, err);
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return err;
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}
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/* Finally apply the TX VID on this port and on the CPU port */
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err = dsa_8021q_vid_apply(ds, port, tx_vid, BRIDGE_VLAN_INFO_UNTAGGED,
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enabled);
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if (err) {
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dev_err(ds->dev, "Failed to apply TX VID %d on port %d: %d\n",
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tx_vid, port, err);
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return err;
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}
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err = dsa_8021q_vid_apply(ds, upstream, tx_vid, 0, enabled);
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if (err) {
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dev_err(ds->dev, "Failed to apply TX VID %d on port %d: %d\n",
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tx_vid, upstream, err);
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return err;
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}
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if (!enabled)
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err = dsa_8021q_restore_pvid(ds, port);
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return err;
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}
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EXPORT_SYMBOL_GPL(dsa_port_setup_8021q_tagging);
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struct sk_buff *dsa_8021q_xmit(struct sk_buff *skb, struct net_device *netdev,
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u16 tpid, u16 tci)
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{
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/* skb->data points at skb_mac_header, which
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* is fine for vlan_insert_tag.
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*/
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return vlan_insert_tag(skb, htons(tpid), tci);
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}
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EXPORT_SYMBOL_GPL(dsa_8021q_xmit);
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/* In the DSA packet_type handler, skb->data points in the middle of the VLAN
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* tag, after tpid and before tci. This is because so far, ETH_HLEN
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* (DMAC, SMAC, EtherType) bytes were pulled.
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* There are 2 bytes of VLAN tag left in skb->data, and upper
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* layers expect the 'real' EtherType to be consumed as well.
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* Coincidentally, a VLAN header is also of the same size as
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* the number of bytes that need to be pulled.
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*
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* skb_mac_header skb->data
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* | |
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* v v
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* | | | | | | | | | | | | | | | | | | |
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* +-----------------------+-----------------------+-------+-------+-------+
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* | Destination MAC | Source MAC | TPID | TCI | EType |
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* +-----------------------+-----------------------+-------+-------+-------+
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* ^ | |
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* |<--VLAN_HLEN-->to <---VLAN_HLEN--->
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* from |
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* >>>>>>> v
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* >>>>>>> | | | | | | | | | | | | | | |
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* >>>>>>> +-----------------------+-----------------------+-------+
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* >>>>>>> | Destination MAC | Source MAC | EType |
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* +-----------------------+-----------------------+-------+
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* ^ ^
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* (now part of | |
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* skb->head) skb_mac_header skb->data
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*/
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struct sk_buff *dsa_8021q_remove_header(struct sk_buff *skb)
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{
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u8 *from = skb_mac_header(skb);
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u8 *dest = from + VLAN_HLEN;
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memmove(dest, from, ETH_HLEN - VLAN_HLEN);
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skb_pull(skb, VLAN_HLEN);
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skb_push(skb, ETH_HLEN);
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skb_reset_mac_header(skb);
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skb_reset_mac_len(skb);
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skb_pull_rcsum(skb, ETH_HLEN);
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return skb;
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}
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EXPORT_SYMBOL_GPL(dsa_8021q_remove_header);
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static const struct dsa_device_ops dsa_8021q_netdev_ops = {
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.name = "8021q",
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.proto = DSA_TAG_PROTO_8021Q,
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.overhead = VLAN_HLEN,
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};
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MODULE_LICENSE("GPL v2");
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MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_8021Q);
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module_dsa_tag_driver(dsa_8021q_netdev_ops);
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